shade AND blackwater conundrum

The best things to plant would be trees.  Want functions of seasonal shade, food (potentially), aesthetics, and kind of water processing.

Everyone seems pretty clearly in agreement that the worst thing to do would be plant a willow tree in a leach field.  

And someone's bright idea was to put the leach field on the south side of the house.

But maybe there's another solution to this that we're just not seeing.

I looked on Art Ludwig's site and found one rather theoretical thing that sounds awesome, but needs wasterwater management level expert.

I don't know much about this topic at all, and this is for a beginning permie/non-permie-whom-I'm-dragging-into-this.  She just bought this house
--in coastal North Carolina
zone 8
heavy rain all year
grass on the soil currently

I'm thinking a little provocative operations are in order.  I'd love to do it now but then I'd be being rude to her on her birthday.  So make someone's birthday with some awesome permaculture ninja please! thanks!

So far my idea is vines--on strings down from the eve so they don't bother the house--lablab peas for starting? some legume and then grape following.  I would hope the grape would self-trellis after a few years, though I don't know.

Potential downsides are you would have to get up on a ladder to trim the tops of the vines in a few years, but better than a willow eating the septic system.

Other ideas?

I ahve the sense there sould be a way to turn the problem into a solution!

" The Spruce" says these trees would do well in a leach feild due to their shallow roots
Dogwood trees
Japanese maple trees
Eastern redbud trees
Cherry trees
Azalea shrubs
Boxwood shrubs
Holly shrubs

To contain the roots of other hedge plants, maybe 55 gallon drums, with slits cut in the bottom and sides, sunk a foot or so into the ground?
I wouldn't trust it to contain bamboo or willow, but sand plums or hazelnuts should be ok,and allow them to enjoy acres to the nutrients.

Thanks William.

I'm thinking she won't want to go for 55-gallon drums for aesthetics...but maybe nice pots.  But there's also budget constraints.

The vines look like a good temporary first-year solution, and if they reach the roof that's a bridge she can cross when she comes to it.

That buys some time for more clear decisions about a host of things:
how much are they going to use the toilets and showers?
will they install a greywater system?
how well does the septic system work, and how often is it needing to be pumped?
any surprises the previous owner didn't tell them about (they don't really know why they sold the place...)

There seem to be differing opinions about even shallower trees and leach fields.

Air potatoes are one possibility if grown in boxes...and only if they're going ot be sure to put down some kind of sheet or tarp to collect them at harvest time.  Don't know if they'll winterkill in that climate (North Carolina).

William Bronson wrote:" The Spruce" says these trees would do well in a leach feild due to their shallow roots
Dogwood trees
Japanese maple trees
Eastern redbud trees
Cherry trees
Azalea shrubs
Boxwood shrubs
Holly shrubs

To contain the roots of other hedge plants, maybe 55 gallon drums, with slits cut in the bottom and sides, sunk a foot or so into the ground?
I wouldn't trust it to contain bamboo or willow, but sand plums or hazelnuts should be ok,and allow them to enjoy acres to the nutrients.

I seem to be coming into this discussion a little late, so I don't see the original question. However with regards to willows in a leachfield - if you design your distribution piping with care then it can be an ideal solution.

Danish Zero Discharge Willow facilities have been in use since the mid 1990s in Denmark and increasingly around the rest of Europe and elsewhere in suitable climates around the world. This is a fully plastic lined basin, backfilled with 1.5m of soil, and then planted with willows. The growing trees keep pace with the input of sewage effluent from the septic tank, and rainfall. In order to prevent clogging of the inlet pipe, a pump fed 40mm pipe is used, positioned in a large void-space plastic unit of c.300mm x 400mm in cross section (called an Exponet bioblock).

An alternative that I've been specifying here in Ireland is a trench infiltrator unit, or a lower cost version which is a 1' twin-walled plastic pipe cut down the middle to form two long gutters that can be placed face down on the infiltration trench base. This allows easy access for the willow roots to the water, but does not provide pipe perforations that the roots can clog.